Bating



UNITED STATES PATENT OFFICE.

CHARLES S. HULL AND PETER S. BURNS, OF BOSTON, MASSACHUSETTS.

BATING.

SPECIFICATION forming part of Letters Patent No. 452,271, dated May 12,1891.

Application filed September 12, 1890.

To all whom it may concern;

Be it known that we, CHARLES S. HULL and PETER S. BURNS, citizens of theUnited States, residing at Boston, in the county of Suffolk, State ofMassachusetts, have invented certain new and useful Improvements inMethods of Eating, of which the followingis a specification, referencebeing had therein to the accompanying drawings.

This invention relates to the treatment of skins and hides, and thenovelty resides in the improved method hereinafter disclosed.

We employ in the treatment of hides or skins or parts thereof as areagent for the neutralization of the alkali employed as a depilatory(said reagent being commonly known as a bate or drench) the sulphonicacids of naphthaline-namely, the alpha and beta mono and disulphonicacids of naphthaline, known under the formulae C H HSQ, and 4 9.,-

The skins or hides or parts thereof are immersed in a warm or coldsolution of the acid of suffic-ient strength or of more than sufficientstrength for the conversion of the alkali existing in the hides orskins, or parts thereof, into its salts. The length of time the skins orhides are subjected to the action of the acid will vary with differentkinds of skins.

It is desirable for best results to use the acids as pure as possible;but good results may be obtained even if the said acid con tains some ofthe impurities incident to its manufacture, such as free sulphuric ormuriatic acid and salts of both, together with traces of the naphthalinesulphonic-acid salts or traces of metals arising from the apparatus inwhich the acid is made.

Serial No. 364,751. (No specimens.)

tained in the hides or skins at the time of treatment, with its or theirnapthaline sulphonic-acid salts. A theoretical amount may, however, beused, based 011 the amount of alkali actually contained in the skins;but more satisfactory results may be obtained by using an excess overthe actual requirements.

The advatages resulting from the use of the naphthaline sulphonic acidsmay be briefly stated as follows: their marked antiseptic qualitieswhich preserve the hide or skin and its parts from dissolution or lossduring the bating process; the avoidance of the introduction of bacteriainto the tan solution or liquors which is attendant upon common methodsand upon the use of acids which induce decomposition; their lack ofaction upon the hide structure itself, except as. a preservative; theextreme solubility of their salts; their lack of action with iron saltsto produce a discoloration of the solution; by the complete removal ofthe alkali or alkaline salts employed as a depilatory, its action uponthe hide or skin fitting it for a rapid combination with the tanningagent, and efiecting in the hide or skin thelightest color of which thehide or skin is capable of taking with the tanning agent employed, andthe production of the greatest weight of leather of which the hideorskin is capable through the avoidance of loss of gelatine.

hat we claim as new is 1. As a step in the art of bating skins andhides, the subjecting of the same to the action of the sulphonic acidsof naphthaline, substantially as specified.

2. The improvement in the treatment of skins and hides, which consistsin converting the alkali of the skins or hides into its salts by theaction of the sulphonic acids of naphthaline, as set forth.

In testimony whereof we affix our signatures in presence of twowitnesses.

CHARLES S. HULL. PETER S. BURNS. lVitnesses: ALBERT A. DAY, WALTER S.Fox.

